Network access points such as those used in Local Area Networks (LANs), Wireless LANs (WLANs) and cellular networks are becoming ubiquitous. From the perspective of a high connectivity it is therefore only a logical consequence that many mobile devices provide support for more than one Network Access Technique (NAT).
WO-A-00/22857 teaches a modular approach in which different network access modules (such as a Local Area Network (LAN) module and a Global System for Mobile communications (GSM) module) are interconnected via a communication bus according to the Universal Serial Bus (USB) standard. Other modules connected to the communication bus such as a Closed-Circuit Television (CCTV) module may then selectively transmit signals via the LAN module on the one hand or via the GSM module on the other.
A. Ghosh et al., “Open application environments in mobile devices: Focus on JME and Ericsson Mobile Functional modules”, Ericsson Review No. 2, Vol. 82, 2005, pages 82 to 91 (ISSN: 0014-0171) describe a further modular approach for mobile devices. This approach is based on a functional module in the form of mobile platform with a digital baseband processor supporting one or more Radio Access Techniques (RATs) such as General Packet Radio Service (GPRS), Enhanced Data for GSM Evolution (EDGE) or Wideband Code-Division Multiple Access (WCDMA). The mobile platform module is an environment that includes all the necessary integrated circuits and software needed to provide wireless network access services and communication services (e.g. for voice, data or multimedia applications), as well as interfaces to make these services available to applications residing within or logically on top of the mobile platform module.
The software and hardware architecture of mobile platform module proposed by Gosh et al. is structured into layers and stacks (see also WO 03/069463). The uppermost layer is an application layer comprising customer and operator applications. A middleware layer permits the applications to access different services that are arranged in individual vertical software stacks. Such services include network access services, data communication services, user interface and codec services, basic application services and operation services. The software stacks are located on top of a hardware abstraction layer, which again provides the appropriate interfaces to the hardware, including GPRS, EDGE and WCDMA components.
EP 1 133 208 A2 teaches a wireless modem comprising a radio board and a digital board. The modem has an interface to output a standard 10Base-T data stream to a personal computer.
EP 1 335 566 A1 relates to a mobile telephone comprising a wireless modem module. The wireless modem module is connected together with a control signal interface and a Personal Digital Assistant (PDA) device to a main controller of the mobile telephone.
In accordance with the modular approach taught by Gosh et al., the mobile platform module may be co-located with an application platform module including a third-party application processor in a mobile device. The third party processor is configured to handle all applications and multimedia functionalities, and the mobile platform module need thus only handle a reduced set of functionalities, such as providing access to a mobile communications network.